Prototype objects never share their map, and hence cannot be in deprecated state.

src/ic/handler-compiler.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/cpu-profiler.h"
 #include "src/ic/call-optimization.h"
 #include "src/ic/handler-compiler.h"
 #include "src/ic/ic.h"
@@ skipping 56 matching lines @@
   Map::UpdateCodeCache(stub_holder_map, cache_name, handler);
   return handler;
 }
 
 
 Handle<Code> PropertyHandlerCompiler::GetCode(Code::Kind kind,
                                               Code::StubType type,
                                               Handle<Name> name) {
   Code::Flags flags = Code::ComputeHandlerFlags(kind, type, cache_holder());
   Handle<Code> code = GetCodeWithFlags(flags, name);
-  PROFILE(isolate(), CodeCreateEvent(Logger::STUB_TAG, *code, *name));
+  PROFILE(isolate(), CodeCreateEvent(Logger::HANDLER_TAG, *code, *name));
 #ifdef DEBUG
   code->VerifyEmbeddedObjects();
 #endif
   return code;
 }
 
 
 #define __ ACCESS_MASM(masm())
 
 
@@ skipping 425 matching lines @@
         DCHECK(elements_kind == DICTIONARY_ELEMENTS);
         cached_stub = LoadDictionaryElementStub(isolate()).GetCode();
       }
     }
 
     handlers->Add(cached_stub);
   }
 }
 }
 }  // namespace v8::internal